Method of and apparatus for producing plaster-boards.



D. E. ROBERTS.- METHOD OF'AND APPARATUS FOR PRODUCING PLASTBR BOARDS.

APPLICATION FILED IEBB, 1909.

Patented Nov. 14, 1911.

6 SHEETS-SHEET 1.

D. B. ROBERTS.

METHOD OF AND APPARATUS FOR PRODUCING PLASTER BOARDS.

APPLICATION FILED FEILB, 1909.

Fatented Nov. 14, 1911.

6 SHEETS-SHEET 2.

D. E. ROBERTS. METHOD OF AND APPARATUS FOR PRODUCING PLASTBR BOARDS.

APPLICATION FILED FEB.8, 1909. 1 ,008,991 Patented Nov. 14, 1911. sSHEETSSHEET s.

mirwsses Qkg 26 D. E. ROBERTS. METHOD OF AND APPARATUS FOR PRODUCINGPLASTBR BOARDS.

APPLICATION FILED FEBJL 1909.

Patented Nov. 14, 1911.

6 SHEETS--SHBET 4.

D..E. ROBERTS.

METHOD OF AND APPARATUS FOR PRODUCING PLASTER BOARDS.

APPLICATION FILED FE]3.8.1909v g gg I Patented Nov. 1 1911.

6 SHEETS-SHBET 5.

D. E. ROBERTS. METHOD OF AND APPARATUS FOR PRODUCING PLASTER BOARDS.

APPLICATION FILED FEB.8.1909.

1,08,991; Patented Nov 14,1911.

6 SHEETi-QHEET fi Law/eases a/Q. 2%,

rooster.

T (L whom it may concern:

ill ilflSED srairns parent canton.

DAVID E. ROBERTS; OF FORT DODGE, IOVI'A.

MIE'IiI-IOID OF AND APPARATUS FOR PRODUCING I?L.ASTER-BOAB\DS.

Be it known that I, DAVID E. ROBERTS, a citizen of th United States,residing at Fort Dodge, in the county of *Webster and State of Iowa,have invented a certain new and 'useful Method and Apparatus forProducing Plaster-Boards, of which the following is a specification.

described method may be practiced and the plaster board produced'bymeans of continuously operating mechanism which is entirely automatic inits operation. I

My invention consists in the construction,

arrangement and combination of the various parts of the device wherebythe objects con templated are attained as hereinafter more fully setforth,- pointed out in-my claims, and illustrated in the accompanyingdrawings,

Figure l shows'a side elevation of the receiving endof an apparatusembodying my invention? Fig. 2jshows'a side elevation of the deliveryendof the same machine. The

{dotted lines in Fig. 2 show the adjacent portions' of the mechanism,which are also shown in Fig. 1, toclearly illustrate therelation-andarrangement of the parts shown in said'two figures. Fig. 3shows a vertical,

central, sectional view of the mechanism shown in Fig. 1. Fig. t showsa' similar view of the part of the machine shownin Fig.2. The dottedlines in said figure show the adjacent portion of the mechanism that is,also shown in Fig. 3 to illustrate the rela- .tive arrangement ofthepa'rts. Fig. 5 shows a top or plan view of the part of theapparatusshown in Fig. 1. Fig. 6 shows a top or plan view of the part ofthe apparatus shown in Fig. 2. Fig. 7 shows a top or nlanview of aportion of one of the edgeforming devices. Fig. 8 shows a detail,transverse. sectionalview on the line 8-8 of High to illustrate theedge-forming devices." Fig. 9 shows an enlarged, detail, sec-Specification of Letters Patent. Patented Nov. 14L, M3111. Applicationfiled February 8, 1909. Serial No. 76,684.

tional view illustrating the means for holding the edges of theplasterconveying belts toward each other to prevent the plaster from movinglaterally from the sides of the belts, and-Fig. 10 shows an enlarged.detail view illustrating the lower end ortions or the frames of theplaster conveying belts to illustrate the means whereby the upper framemay be tilted upwardlyrelativeto the lower frame to permit the cleaningof the adjacent surfaces of both of the conveyer belts.

Referring to the accompanying drawings, I have used the referencenumeral 10 to indicate the main supporting frame of the device. Mountedon this frame is a stationary flat-topped table 11 extendedsubstantially throughout the entire length of the frame. This table isthe one on which the plaster board is'formed. At the delivery end of theframe is a power shaft 12 provlded with a. pulley 13. Mounted on theshaft 12 is a roller 14 and arranged at the other end of the table 11 isa shaft 15 having a roller 16 thereon. An endless conveyer belt 17 ispassed over these two rollers, the upper portion of whichmoves-longitudinally over the table top and the lower portion returnsunder it.

The foundation upon which the plaster board is formed is preferably ofpaper and for this purpose I provide a rotatable shaft 18 adjacent tothe receiving end of the conveyer l7 and on this shaft is a roll ofpaper 19 which is placed on top of the conveyer 17 and which travelswith the conveyer. The first material that is placed upon the paperconsists of a thin layer of plaster in a comparatively wet condition sothat it will easily spread out over the entire layer of paper. To feedthis layer of laster evenly and smoothly over the layer of paper, I haveprovided the following mechanism: The reference numeral 20 indicates awater tank extended transversely of the main frame above thereceivingend of the conveyer. Adjacent to the tank 20 is a conveyerchute 22 having a screW-conveyer 23 therein. This conveyer communicateswith a source of supply for plaster'which, however, is not shown in theaccompanying drawings. The means for operating the conveyer 23 comprisea sprocket wheel 24: on the end of the conveyer chute connected by asprocket chain 25 with a sprocket wheel 26 on a shaft 27 mounted in theframe. The shaft 27 is driven in a manner hereinafter described.

Arranged below the water tank 20 and the conveyor chute 22 an endlessconveyor belt 28 extended around rollers 29 and 30, the said rollers 30having on one end the SPIOClUbWhGBl 26 and a large pinion 31. The bottomof the water tank is perforated so tliat'water may flow slowly throughit to the receiving end of the conveyor belt 28, and. the bottom of thechute 22 is provided with a slotthrough which the plaster may bedischarged to the top of the conveyor belt. Arranged above the upperportion of the conveyer belt 28 is a second conveyor belt 32 which ispassed around. the rollers 33 and 3d, the latter being adjacent to theconveyer trough 22. The upper conveyor belt 33 is driven at aconsiderably higher speed than the lower couvcyer belt 28 by means ofthe small pinion connected therewith and iumesh with the large pinion 31on the shaft of the lower conveyor. In order to prevent material frompassing out laterally between the edges of the said conveyer belts 28.and 32, I have provided the following means, which are fullyillustrated in Figs. 9 and 3. Beneath the upper portion of the belt 28and immediately below thepoint where the water is discharged from thetank 20, I place a shaft 36 having on each end a cone-shaped idlerroller 37 largest atits outer end. edges of the upper portion of thebelt 28 to be elevated above the central portion of the belt so that thewater will not run off the sides of the belt. A number of similar shaftswith idlers thereon are placed under the upper portion of the belt belowthe belt 32 a11d,-above the lower portion of the belt 32, I havearranged one or more snafts 38 with cone-shaped idlers 39 at their endsdesigned to press the side edges of the lower portion of the beltdownwardly and. to ward the belt 28 so that the edges of the belts arethereby held toward each other to thereby prevent the plaster frompassing outwardly between the edges of the belts. It is to be understoodin this connection that the upper belt 32 is arranged to run somewhatfaster than the lower belt 28 and to compress the material passingbetween the belts. Therefore, vthe plaster will be smoothly and evenlydistributed througliout the entire surfaces of the belts but will notbe, permitted to pass out beyond the sides of the belts. In order toprevent the plaster from adhering to the belts, I provide a stationaryscraper 43 for the lower belt 28 and asimilar scraper 41 for the upperbelt 32, hence the material after passing etween the belts willbe'delivered on top of the paper 19 that is traveling along the tabletop 11 on the belt '17.

The next step in the operation of the machine is the delivering on topof the layer of plaster of layer of mete-rial such,

This will cause the side for instance, as hemp. To continuously deliveran even layer of fibrous material on top of the first layer of plaster,I have provided the following mechanism; Mounted on suitable rollersconnected to the machine frame are two endless conveyer belts L2 and 48,the lower portion of the belt 42 being arranged to run close to theupper portion of the belt 43. These belts are arranged to run at thesame speed and the rollers at the lower ends thereof are connected witheach other by the pinions Q4 and 45, the latter pinion being driven bymeans of-a sprocket wheel i6 and chain d7, which chain is driven in amanner to be hereinafter described.

Arranged adjacent to the front of the machine is a table 48 and arrangedadjacent to one end of this table is a series of toothed feeder bars 49arranged parallel with each other and inclined upwardly and towardthebelt 43. two eccentrics 50 mounted on shafts 51 which shafts areEonnccted by means of the sprocket chain 52 and sprocket wheels 53 torun in unison. The arrangement of the eccentrics on the shafts is suchthat the alternate feeder bars move in opposite directions. The lowerends of said feeder bars are adjacent to the end of the table 48 and theupper ends are arranged to discharge on top of the conveyor belt 48. Iprovide for driving the lower shaft 51 by means of a sprocket wheel 54placed on one end thereof and connected by a sprocket chain 55 with asprocketwheel 56 which sprocket wheel is mounted upon the shaft .15 ofthe main conveyer belt 17. In operation with this fiber-feeding device,a large quantity of the fiber is placed upon the tabletop 48 and the oerator feeds it toward the'feeder bars d9. 'Vhen they engage it, itis'carried by them upwardly and is evenly distributed throughout theentire surface of the feeder bars so that, when deliveredbetween thebelts 42 and43, there will be an even and uniform layer of the fiber andthis layeris then discharged by the belts 42 and 43 on top of the layerof plaster on the paper 19.

The next step'in the operation of the machine is the depositing of asecond layer of plaster preferably thicker than the first on top of thelayer of fiber. For this purpose,

-I have provided the following mechanism:

Mounted in the frame 10 above the conveyor belt 42 are two conveyerbelts 57 and 58 similar to the belts'32 and 28- before described. Theseconveyer beltsare also provided with idlcrs similar to the idlers 37 and39 before described in connection with the belts 32 and 28. They arealso provided with scrapers 59 and 60 similar to the scrapers 41 andll). Above the conveyer belt 48 is a water supply tank 61 communicatingwith a supply aipe 62 and having openings therein to discharge. on topof the conveyer belt 58 1 distributed. For this reason, I have andadjacent to it is a conveyer chute 63 having a conveyer 6d thereinarranged to discharge plaster downwardly on top of the belt 58. It isintended that the layer of plaster delivered by the belts 57 and 58 besomewhat thicker and in a less moist condition than the layer deliveredby the belts 32 and 28 and it is-therefore necessary that the materialbe thoroughly worked and evenly pro.- vided gearing devices at the endsof the rollers over which the belts 57 and 58 pass,

frame, as clearly shown in Fig. of the.

drawings, is supported at its lower end by means of links 71' pivotedto,the shafts of ,the adjacent rollers. The up or end of the frame 70 isprovided with a b ock 72 having its lower face inclined downwardly andaway from the delivery end of the conveyers. This block 72 rests upon amating inclined block 73 on the main frame. By this warrangement, theupper conveyor will be.

held by gravity downwardly and toward the lower conveyer and wheneverdesired the upper conveyer may be' elevated away from the lower one withthe links 71 serving as pivots, so that access may be had to theadjacent surfaces of the conveyer belts. The said belts 57 and 58 willdeliver the material in a comparatively smooth and uniform manner fromthe delivery ends thereof.

Below the delivery ends of the belts 57 and. 58 are two additional beltsfor smoothing and flattening out the layer of plaster. The lower belt issupported upon the lower roller 74c and an upper roller or pulley 75 andthe belt 76 passes around them. Said lower roller 7 4 is provided with alarge inion 77 and a sprocket wheel 7 8 to which the chain 47 beforedescribed is connected. A scraper blade 79 is provided for the belt 76and an auxiliary roller 80 is placed under the upper portion of the belt76 at the point e the material is discharged to said belt from the belts57 and 58. Above the roller 74 is a roller 81' vertically adjustablerelative to the roller 74 by means of the setscrews 82 so that saidrollers may be adjusted to any roper distance relative to each other. Adacent to the said roller is a roller or pulley 83 and a belt 84 ispassed 60 around the rollers 83 and 81. The shaft of the roller 81 isprovided with a small pinion 85 meshed with the pinion 71 'so that theupper belt 84 is driven at a greater speed than the lower belt 76. Ascraper 86 is pro- 65 vided for the belt 84:. By this arrangement.

it is obvious that the material, after being; first flattened outand'evenly. distributedi'by the belts 57 and 58,,will then be discharged'1 .terial such as burlap on the top of the up? 3Q per layer of plaster;For; th s purpose, I provide a shaft 87 on the machine frame and on thisshaft is a roll 88 of material v such as burlap. The end of the roll'ofjburlap is then extended downwardly on top offthe layer of plaster. Inthe drawings, 1" have shown a second roll ofb' irlap'in'po si tion to beused when the first roll ei, hausted.

In order to firmly press all of the layersf o together and make asmooth' and uniform plaster board, I provide, in the table 150 5511; aroller 89 connected by a sprocket gearing with the power shaft .12. Thisgearing comprises a sprocket wheel 90 onthe roller shaft, a sprocketchain 91 connected withjhand a sprocket wheel 92 on the power shaft 12also connected with the sprocket chain 9f1.'

Ibis extends p yumugh the. 7' table top to engage the under surface ofth plaster board. Above the roller 89 is a roller 93 mounted in anadjustable bearing provided with an adjusting screw 94. Adacent to theroller 93 is a sir'nilarroller 9 5 also provided with an adjustablebearing. Adjacent to the roller 95is athird roller 96 which roller isnormally supported in a plane slightly higher than that of the roller 93and passed around the rollers93 and 96 is an endless belt 97. Iprovidefor' driving 11' the rollers'by means of ainidn 98 on the shaftof the roller 96 which pinio' 'ri isfi'n mesh with apinion 99 on theshaft 89. The layer of burlap extends under'the' .belt 97j and as theplaster board passes'betwden; thiebl] rollers 89 and 93 it obviouslyant, "be smoothed and made of regular andunifo'rm thickness throughoutits entirewidth and] .j the various layers will be firInlyfcornpreshsed. This operation will force s'omeof tli e plaster .1 20 up through thelayer of burlap and, in (ha to prevent the belt 97 fromndlieringto'fith'ei plaster that extends up through the layerbf" burlap, Ielevate the rear end portion of. the

belt 97 in the manner clearly shown in'F 4 so that said belt graduallydetaches itse from the layer of 'burlap'aiid' 'the plaster, board isthereby prevented"froni'adhering t the belt 97. In order to hold theplaster boardaccurately centered over the main conveyor belt 17 and inorder to prevent any of the material of the plaster board from movingout beyond the sides of the conveyor belt 17 and for the purpose ofmaking a plaster board of exactly uniform width throughout, I haveprovided edge forming devices as follows: A similar edgeforming deviceis arranged on each side of the conveyor belt 17. and hence only onewill be hereinafter fully described. Adjacent to the delivery end of thetable 11 is a vertical shaft having a sprocket wheel 101 fixed to itsupper end. on its lower end is a beveled gear wheel 102 in mesh with abeveled gear wheel 103 on a shaft 104, which shaft is provided with asprocket wheel 105 connected by a sprocket chain 106 with a sprocketwheel 107 on the power shaft 12. By this arrangement, the sprocketwheel. 101 is made to rotate, during the operation of the machine, atthe same rate of speed that of the main conveyor belt 17. At theopposite end vof the machine frame is an upright shaft 108 which isprovided with a sprocket Wheel similar .to the sprocket wheel 101. Asprocket chain 109 is passed around the sprocket wheels 101 and 108andeach link-thereof is provided with a flat plate 110 which plate 18connected with the adjacent link of the chain by means of pivotpins 111so arranged that each plate may .have a slight tilting movement relativeto the link to which it is attached. The adjacent edges of the plates110 are beveled or inclined at 112 and said parts are so arranged thatthe said plates will all stand in line with each other at a point abovethe;

side edges of the belt-17. as lower edges of the plates preferably restupon or close to the top surface of the belt 17 and the top edges of theplates areabove the layer of plaster board. In this way, the plasterboard is-accnrately centered on top of the belt 17 and none of thematerial on it can work out beyond the sides of the belt 17 and theplaster board is made of exactly uniform width throughout. The object inhaving the.

plates 110 pivotally connected with the links and beveled at their endsis that said plates may move in a straight line until they ,pass aroundthe sprocket wheel 101 so far that the plates may tilt withoutprojecting one of their ends into the adjacent edge of the plaster boardand so that they may withdraw from the plaster board withoutcaus ing theplaster board'to adhere to theml, 'Obviously, if a continuous belt wereem.-

ployed for this purpose, it would adhere to the edges of the plasterboard and leave the edges in a rough and unfinished condition, whereas,by means'of the pivoted and beveled plates, the edges of the plasterboard are left smooth and even.

In order to impart motion to the shaft 27,

'of plaster on top of the liber, t

the last layer of plaster,

I have connected. it by a sprocket'gearing device with the shaft of thelower roller which supports the belt :3, which lower roller is driven bymeans of the chain 4-? as before described. The sprocket gearing devicecomprises a chain 113 'lCl sprocket wheels 1M: and 115 on said shafts,as clearl shown in Fig. 1, and -in order to drive the conveyor bolts 57and 58, I employ a sprocket gearing device 11 1 connecti the lowerroller of the conveyor belt 42 'th the shaft of the conveyor belt 57,asshown. in Fig. 1.

' in practical operation, it obvious that all of the machinery may bedriven by power applied to the main power shaft, or, if (lo-- sired, anyone or more of the operations of the machine maybe carried on-by hand;As of each of the various parts of the machine have been described indetail, it is be lieved that the operation of the machine as a wholewill be readily unde stood.

My improved method consi. in first providing a continuous layer of peror the like, then cont nuously app'l thereto a thin, n1oi -lv lax ofplaster "w (l1 will ad here to the lay r of paper, T n applying, on topofthe plaster, a continuous layer of fiber which will adhere to the i yer of pisster, then applying a second co a. layer of material such asbin ien firmly compressing the layers to to them of uniform thicknessand to cause the plaster to thoroughly commi 'le with the layer of fiberand the layer o; burlap and also to continuously smooth out the edges ofthe plaster board as it continuously. moves over the tableon which it issupported. It. is obvious that th various operations may be performed.wllOlly or partially by hand, and, hence, tent on the machine orapparatus itself an ht be 1115111 licient to protect the method orprocess,

I claim as my invention.

1. In a machine of the class described, the combination of ,a movablesupport, means for feeding a sheet of flexible material to the movablesupport','n1-2aus for feeding alayer of plaster on top of the flexiblematerial,

means for feeding a second flexible sheet on top of the plaster and apressing device to operate upon the second flexible sheetafter it hasbeen placed on the plaster, said press.- ing device comprising.a surfaceca .able of moven'ient in the same direction as t 1e mate Jlfil on whichit is operated and being arranged in position to firmly engage the material; atone end and being inclined away'from the end of the machinetoward which the. material is moving.

the material at .2. Ina machine of the class described, the combinationof a. movable support, means. for, feeding a sheet of flexiblematerialto the movable support, means for feeding a.

act

plaster, comprising two endless conveyor weaselward end and elevatedabove the material at its rear end.

3. In a'machine of the class de'scribod, means for supplying acontinuous layer of bolts having their adjacent portions slightly spacedapart and arranged for movement in the same direction, and means fordepositing a layer of. plaster on the upper surface of the lowerconveyor belt, and means for supplying water on the upper surface of thelower conveyor belt in advance of the plaster.

4. In a machine of the class described, means for supplying a continuouslayer of plaster, comprising two endless conveyor belts having theiradjacent portions slightly spaced apart and arranged for movement in thesame direction, and means for depositing a layer ofplaster on the upper"surface of tholower conveyor belt, and means for turning up the sideedges of the upper portion of the lower conveyor belt.

5. In a machine of the class described, means for supplying a continubuslayer of plaster, comprising two endless conveyor belts having .theiradjacent port-ions slightly spaced apart and arranged for movement in 1the same direction, and means for deposit inga layer of plaster on theupper surfacc of the lower conveyor belt, and means for turning up thesideedges of the upper portion of the lower conveyor belt, and means forturning down thesidc edges of the lower portion of the upper conveyorbelt.

6. In a machine of the class described, means for supplying 'acontinuous layer of plaster, comprising two endless conveyer boltshaving their adjacent portions slightly spaced apart and arranged formovement in the same direction, and means for depositing a layer ofplaster on the upper surface of the lower conveyor belt, and means forturning up the side edges of the-upper portion of the lowerconveyerbelt, and means for turning down the side edges of the lowerport-ion ofthe upper conveyor belt, and a stationary scraper at thedischarge end of each conveyor belt. 7

7 In a device of the class described, the combination of a conveyor beltinclined downwardly and toward the delivery end of the device, means forsupplying water to the top surface-of the conveyor belt for preventingplaster from adhering to it,

means for holding up the side. edges of said conveyor belt to preventthe water from running 05 of the sides of the belt, and

with their adjacent portions arranged-close -to each other, means formoving them so that the adjacent portions of the belts travel in thesame direction. and means for. holding the side edges of the adjacentportions of both belts toward each other. f

9. In a device of the classdescribednthe combination of two endlessconveyor belts with their adjacent portions arrangedclose to each other,means for moving-themso that the adjacent portions of the belts travelin the same direction, and means for holding the side edges of theadjacent portions of both belts toward-- each other, said meanscomprislng a number of' shafts extended transversely of each belt,,andcone-shaped rollers-on said shafts to engage thoedgo portions ofthebelts. I

10. In a device of the one arranged abovethe other and designed toreceive plaster between .them, means for moving the lower conveyor belt,and means for moving the upper conveyor bolt. sothat ,the part thereofadjacent to the lower belt will move in the same direction and .at anincreased speed. j

11. In a "device of the class described, the combination of an endlessconveyor belt, means for supplying plaster to the upper surface thereof,a second endless conveyor belt above the first, a frame for supportingthe upper conveyor belt, links for pivotally supporting the dischargeend of said upper frame, and an inclined support for the other end ofsaid frame, for the purposes stated.

12. In a device of the class described, the combination of two rollers,an endless conveyor belt passed around them, a second endless conveyorbelt above the first, two rollers for said second conveyor belt, linksconnecting the rollers of the upper and lowerconveyer belts at one end,and an inclined support for the other end oftho upper conveyor belt.

13. In a device of the class described, a means for delivering acontinuous layer of fiber, comprising a series of toothed bars, meansfor oscillating them, and two endless conveyor belts arranged one abovethe other in position to receive the fiber from the dis charge end ofsaid oscillating bars, and means for operating said conveyor belts withtheir adjacent portions moving in the same direction.

14. In a device of the class described, the

combination of a table top and a series of class described; thecombination of two endless conveyor belts,

from the table, means for oscillating said toothed bars, the alternateones thereof being arranged to move in opposite directions.

15. In a device of the class described, the combination of anendlessconveyer belt, arranged for movement ina substantially horizontaldirection, means for applying plaster to said belt, and a second endlessconveyer belt above the first and so arranged that its forward portionwill engage the material on the first belt and its rear portion will beelevated slightly above said material, and means for operating thelatter belt, said parts being so arranged that theupper belt willgradually move away .from the material on the lower belt so that ihematerial will not adhere to the upper ell:-

16. 111 a device of the class described, the combination of a beltarranged for horizontal movement, meansfor applying plaster to the belt,two rollers arranged transversely above the layer of material on thebelt, means for independently adjusting them toward and from the belt, athird roller in the rear of the first two and elevated above the rear ofthe first two and elevated above them, an endless'belt passed aroundsaid three rollers, said parts being so arranged that the said upperbelt will have its lower portion inclined rearwardly and away from thematerial on the lower belt, and a roller arranged below the lower beltin line with the first one of the rollers above the lower belt, for thepurposes stated.

18. The method of producing plaster board which consists in providing acontinuous sheet of flexible material. and continuously advancing same,then applying a continuous layer of plaster in moist condition on top ofthe sheet, then applying a continuous layer of fabric such as burlap ontop of the layer of plaster and then applying a pressing movement to thelayer of fabric, said pressingmovement being applied by a device havingits pressing surface moving in the same direction the material and heldfirmly in contact with the material atits forward portion and heldslightly away from the material at its rear portion.

Des Moines, Iowa, Jan. 7 1909.

DAVID E. ROBERTS.

W itnesses T. B. Kunsnaw, T. l BUSBY.

